The Picatinney accessory mounting rail for AR type rifles is available in a variety of styles. Accessories which can be mounted on a Picatinney include, for example, advanced sights which replace the traditional iron sights. The Picatinney rail is named for the U.S. Army Picatinney Arsenal and has been described in U.S. Military standards, such as MIL-STD-1913 (AR).